adding fusion docs and tests

[SVN r34920]

test/sequence/tie.hpp

@@ -0,0 +1,85 @@
+/*=============================================================================
+    Copyright (c) 1999-2003 Jaakko J<>rvi
+    Copyright (c) 2001-2006 Joel de Guzman
+
+    Use, modification and distribution is subject to the Boost Software
+    License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+    http://www.boost.org/LICENSE_1_0.txt)
+==============================================================================*/
+#include <boost/detail/lightweight_test.hpp>
+#include <boost/fusion/sequence/intrinsic/at.hpp>
+
+#if !defined(FUSION_AT)
+#define FUSION_AT at_c
+#endif
+
+#if !defined(FUSION_MAKE)
+#define FUSION_MAKE BOOST_PP_CAT(make_, FUSION_SEQUENCE)
+#endif
+
+#if !defined(FUSION_TIE)
+#define FUSION_TIE BOOST_PP_CAT(FUSION_SEQUENCE, _tie)
+#endif
+
+namespace
+{
+    // something to prevent warnings for unused variables
+    template<class T> void dummy(const T&) {}
+
+    // no public default constructor
+    class foo
+    {
+    public:
+
+        explicit foo(int v) : val(v) {}
+
+        bool operator==(const foo& other) const
+        {
+            return val == other.val;
+        }
+
+    private:
+
+        foo() {}
+        int val;
+    };
+}
+
+void
+test()
+{
+    using namespace boost::fusion;
+
+    int a;
+    char b;
+    foo c(5);
+
+    FUSION_TIE(a, b, c) = FUSION_MAKE(2, 'a', foo(3));
+    BOOST_TEST(a == 2);
+    BOOST_TEST(b == 'a');
+    BOOST_TEST(c == foo(3));
+
+    FUSION_TIE(a, ignore, c) = FUSION_MAKE((short int)5, false, foo(5));
+    BOOST_TEST(a == 5);
+    BOOST_TEST(b == 'a');
+    BOOST_TEST(c == foo(5));
+
+    int i, j;
+    FUSION_TIE(i, j) = FUSION_MAKE(1, 2);
+    BOOST_TEST(i == 1 && j == 2);
+
+    FUSION_SEQUENCE<int, int, float> ta;
+
+#if defined(FUSION_TEST_FAIL)
+    ta = std::FUSION_MAKE(1, 2); // should fail, tuple is of length 3, not 2
+#endif
+
+    dummy(ta);
+    
+    // ties cannot be rebound
+    int d = 3;
+    FUSION_SEQUENCE<int&> ti(a);
+    BOOST_TEST(&FUSION_AT<0>(ti) == &a);
+    ti = FUSION_SEQUENCE<int&>(d);
+    BOOST_TEST(&FUSION_AT<0>(ti) == &a);
+}